Dental mallet



(No Model.)

J. B. ODELL.

DENTAL MALLET.

No. 256,850. Patented Apr.25, 1882.

6 inmx wmm/ 7Q; amp.

UNITED STATES PATENT OFFIcE.

JOHN B. ODELL, OF CHICAGO, ILLINOIS.

DENTAL MALLET.

SPECIFICATION forming part of Letters Patent No. 256,850, dated April 25, 1882,

Application filed December 12, 1881.

rectangular form, so that the stem of the mallet, which is made of brass or other non-magnetic substance and actuated by the armature, works up and down through the center of the cores. In this way it will be seen the instrument is made symmetrical, and may be much more conveniently handled in the use for which it is designed than if it be unevenly balanced on one side or the other; and being thus of a cylindrical form, the electrical part of the apparatus may be compactly inclosed in the rubber casing which forms part of the handle or frame or the instrument. The electric circuit is broken at or near the end of the stroke of the mallet, so as not to impede its force. This I do by means of a spring-contact operated by a small circuit-breaking rod or piston actuated by an arm projecting from the armature, the circuit-breaking rod being provided with a stop and an adjustable collar, so that when the stroke is nearly finished this arm, impinging against the stop on the rod, will thereby break the circuit. By adjusting the collar any desired length of stroke may be given. To aid in the adjustment of the instrument and to limit the retraction of the mallet-stem after the blow is given, an adjust able screw-stop is inserted in a brace or angle pieceprojectingovcrtheendofthemallet-stem. The retraction ofthe mallet-stem from the blow, as well as that of the piston in which the plugging-tool is mounted, is efl'ected by means of springs; and the apparatus is set in motion by means of a pin passing through a slot near the end of the mallet and through a ferrule surrounding the handle part ot'the instrument. By slipping the ferrule up the mallet-stem is permitted to be retracted by the spring, thus drawing back the circuit-breaking rod until the spring-contact closes the circuit.

In the accompanying drawings, which form (No model.)

a part of this specification, and in which simi-' lar letters of reference indicate like parts, Figure l is a side elevation of a full-sized device embodying my invention. Fig. 2 is a central longitudinal section of the same onethird enlarged. Fig. 3 is a top or plan view, also enlarged. Fig. 4 is a section on line a: :v of Fig. 2. Fig. 5 is a section on line 113 of Fig. 2. Fig. 6 is an enlarged detail of the cir unit-breaking mechanism, and Fig. 7 is a diagram of the circuits.

In the drawings, A represents the shell or casing, preferably made of hard rubber, in which the electro-magnets are inclosed and up on which a part of the mechanism is mounted. The cores B B of the magnets are provided with a central hole for the mallet-stem O, and are arranged on the same axial line with each other.

I) is the heel-plate, and b the armature, each of which, it will be observed, are of a s mewhat semi-rectangular form,so as to partially embrace one of the coils of the magnet. The mallet-stem passes through suitable holes in the ends of the armature,one of said holes being provided with screw-threads whereby the mallet-stem is secured to the armature.

D is an angle-piece, secured to the top of the hard-rubber head (I of the coil by means of a screw or otherwise; and l) is a set-screw, the end of which projects over the end of the malletstem to limit its upward movement and to alford additional means ofadjusting the length of the mallet-stroke. The mallet-stem O is made of brass, so that the magnetism of the cores B B will not interfere with its free movement.

O is the mallet, which is secured to or made parcel with the mallet-stem. It is provided with a hard-rubber or other suitable cushion, c, on its end to break the shock of the blow.

E and E are the coils, and d, d, d and d are the hard-rubber heads, between which the wire of the coils is wound. The head (1 serves as a base-plate upon which to mount the con tact a and the spring-contact a,whieh is made of spiral form. The contact-breaker (6 passes down through suitable holes in the heads (I and d and projects over the end of the spring-con tact a. This rod a is provided near its upper end with a stop, a and an adjustable collar, a", which are set at about such distance apart as it is desired the length of the mallet-stroke shall be. i

The contact-breaker is actuated by means of a small yoke or arm, a secured to the upper end of the armature. When the armature is drawn down by the magnetized cores until the arm or projection a impinges against the stop a the further movement of the armature will cause the rod a to press down the end of the spring a, and thus break connection between a and c,thus demagnetizing the cores and releasing the armature, when the mallet-stem and armature will be retracted by means of the coil-spring G surrounding the mallet. As the mallet-stem is withdrawn by the spring the arm a after it comes against the collar aflwill lift the contact-breaker a with it, thus permitting'the spring-contact a. to make connection with contact a, when the stroke will be repeated, the same as before.

The stop or set-screw D should be so adjusted as to raise the circuit-breaker only such distance as may be necessary to break the circuit. The coil-spring G- surrounding the mallet presses at one end against a shoulder, g, on the mallet, and at the other end against a collar, 9, resting on the end of the tubular heador sleeve H, in which the tool-holder H is mounted.

The sleeve or handle K is secured to the end of the shell A and incloses the coil-spring G in the annular space surrounding the mallet. The outer surface of this handle is knurled 0r roughened, so that the adjustable fingerrest k, which is mounted loosely on the conical threaded split sleeve or collar may be securely fixed in any desired position on the bandle by means of the conical threaded nut 7c.

The tubular head H is secured to the end of the sleeve K by screw-threads, so as to he ad ju'stable thereon, and is provided with an interior shoulder, h.

h is a light coil-spring surrounding the toolholder H, resting at one end against the shoulder h and at the other end against a shoulder, 7L2, on the tool-holder. This spring serves to keep the tool-holder in position to receive the blow of the mallet. Near the end of the mallet"there is a slot. j, through which passes a pin,j, terminating in the collar J, surrounding the sleeve K at its junction with the tubular head H. A coil-spring,j inclosed within the collar J and hearing at one end against a shonlder,j on said collar and at the other against the end of the sleeve K. serves to DIt'SS this collar into the position shown in Fig. 2, thus holding the mallet down and permanently breaking the circuit. When the operator gets the tool in position and is ready to commence plugging, by simply pulling this collar up with his thumb or finger and turning it slightly until thepinj rests in the end of the slotj in the sleeve K the instrument is put in operation. Ordinarily, however, the operator simply raises and holds the collar up with his thumb.

N is a curved spring, one end of which is secured to the circuit-breaker a, and the other bears against the interior of the shell A for the purpose of steadying the motion of the cirunit-breaker.

a and a are the binding-posts secured to the head (I.

The arrangement of the circuit is as follows: from the battery to binding-post n, thence to upper coil, to lower coil, to spring-contact ct, to contact a, to binding-post a, and thence to battery. 7

The plugging-tool N is secured in the end of the tool-holder by screw-threads or other suitable means, so as to be readily removed for the purpose ofsubstitutin g other tools, as may be required.

I have shown and described what I consider the best mode of practicing my invention, and it will be observed that the same may be used as an electric pen by simply substituting the pointed stylus or perforator in place of the plugging-tool and making the mallet-stem, mallet, and tool-holder continuous, and also for other analogous uses, and I do not wish to limit myself to its use as a dental mallet.

I claitn-- i 1. The combination, with an electro-magnet having hollow cores arranged axially with each other, of the mallet-stem mounted in said hollow cores and the bent armature secured to said mallet-stem for actuating the same, substantially as specified.

The combination, with an electro-magnet having fixed hollow cores arranged axially with each other and connected by a heel-plate, ofa movable non magnetic mallet-stem mount) ed in said hollow cores and an armature secured to said mallet-stem for actuating the same, substantially as specified.

3. The combination, with an electro-magnet having fixed cores arranged axially with each other, of a bent reciprocating armature secured to a reciprocating mallet-stein, substantially as specified.

4. The combination of the mallet and mallet stem, spring torretracting the same, an electro-magnet ha ring hollow cores arranged axially with each other, shell inclosing said magnet, coil-heads, spring contact, circuit-breaker provided with stop and adjustable collar, and an aim secured to the armature for actuating the circuit-breaker, substantially as specified.

5. The combination, with an clectro-magnet, of the mallet and mallet-stem, spring for re tracting the same, adjustable stop to limit its upward motion, spring-contact, and circuit breaker provided with stop and adjustable collar, and arm secured to the armature for actuating said circuit-breaker, substantially as specified.

6. The combination, with the handle K, pro vided with roughened exterior surface, of the finger-rest mounted on an adjustable conical split threaded sleeve and conical threaded out for securing said sleeve in position on the handle K, substantially as specified.

'7 The combination of handle K, provided with bent slotj, hollow head H, ferrule J, pro- I cuit by movement of the mallet-stem, and a 10 vided with pin j, and mallet provided with sliding ferrule, J, mounted on said handle K slot j, substantially as specifier and connected with the mallet-stem, whereby 8. The combination of shell A and the hanthe circuit may be broken at the will of the die K, provided with an adjustable finger-rest, operator, substantially as specified.

with the mallet-stem and spring for retracting JOHN B. ODELL. the same, an electro-magnet having cores ar- Witnesses:

ranged axially with each other inclosed within '1. EVERETT BROWN,

said shell A, mechanism for breaking the cir- EDMUND ADCOOK. 

